Conventionally, a pneumatic sphere comprises a rigid exterior envelope, for example metallic, composed of an upper part and a lower part connected together or formed in a single piece, and a deformable flexible membrane fixed at the interior of the envelope at the region of an interface between the upper and lower parts. The membrane thus defines an upper chamber for receiving, for example, a gas, and a lower chamber for receiving, for example, a liquid. In this case, the lower chamber communicates with the hydraulic circuit of the suspension of a vehicle.
Such a sphere is already used for replacing the spring of a MacPherson type suspension.
In the interior of the sphere, the pressure of the liquid is generally between 0 and 250 bar in normal operation.
Fortuitously, the pressure can increase considerably and can reach several times the pressure of use.
It has then been possible to observe the explosion of the sphere and violent ejection of the interior components from the sphere.
An explosion constitutes a great danger to the user of the vehicle.